linux/sound
Takashi Iwai a393318673 ALSA: timer: Fix mutex deadlock at releasing card
When a card is disconnected while in use, the system waits until all
opened files are closed then releases the card.  This is done via
put_device() of the card device in each device release code.

The recently reported mutex deadlock bug happens in this code path;
snd_timer_close() for the timer device deals with the global
register_mutex and it calls put_device() there.  When this timer
device is the last one, the card gets freed and it eventually calls
snd_timer_free(), which has again the protection with the global
register_mutex -- boom.

Basically put_device() call itself is race-free, so a relative simple
workaround is to move this put_device() call out of the mutex.  For
achieving that, in this patch, snd_timer_close_locked() got a new
argument to store the card device pointer in return, and each caller
invokes put_device() with the returned object after the mutex unlock.

Reported-and-tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-10-30 22:54:56 +01:00
..
ac97 ALSA: ac97: Fix double free of ac97_codec_device 2019-07-23 14:16:11 +02:00
aoa ALSA: aoa: onyx: always initialize register read value 2019-07-29 09:21:39 +02:00
arm treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
atmel treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
core ALSA: timer: Fix mutex deadlock at releasing card 2019-10-30 22:54:56 +01:00
drivers treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
firewire ALSA: bebob: Fix prototype of helper function to return negative value 2019-10-26 09:06:20 +02:00
hda Revert "ALSA: hda: Flush interrupts on disabling" 2019-10-28 11:47:59 +01:00
i2c ALSA: i2c: ak4xxx-adda: Fix a possible null pointer dereference in build_adc_controls() 2019-07-26 14:25:37 +02:00
isa ALSA: sb: remove redundant assignment to variable result 2019-08-14 17:44:06 +02:00
mips treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 176 2019-05-30 11:29:19 -07:00
oss sound: dmasound_atari: Mark expected switch fall-through 2019-07-30 09:36:13 +02:00
parisc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 176 2019-05-30 11:29:19 -07:00
pci ALSA: hda - Fix mutex deadlock in HDMI codec driver 2019-10-30 15:32:37 +01:00
pcmcia treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
ppc ALSA: ps3: Remove Unneeded variable: "ret" 2019-07-10 11:53:31 +02:00
sh treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 273 2019-06-05 17:30:30 +02:00
soc ASoC: Fixes for v5.4 2019-10-21 14:05:26 +02:00
sparc ALSA: sparc: Mark expected switch fall-throughs 2019-07-30 09:37:01 +02:00
spi treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
synth treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
usb ALSA: usb-audio: Add DSD support for Gustard U16/X26 USB Interface 2019-10-24 12:30:06 +02:00
x86 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 285 2019-06-05 17:36:37 +02:00
xen ASoC: Updates for v5.3 2019-07-08 14:45:34 +02:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile
ac97_bus.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
last.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
sound_core.c sound: fix a memory leak bug 2019-08-08 08:18:32 +02:00